Reciprocating bender for making successive bends in metal tubes or rods



Feb, 24, 1948;.

G. E-ENwooD RECIPROCATING BENDER FOR MAKING SUCCESSIVE BENDS IN METAL TUBES OR RODS Filed Dec. 27, 1945 4 Sheets-Sheet l INVE TQR. GearseC-weenwood 1 W ATT'Y.

Feb. 2% 194. G. GREENWOOD 2,436,542

RECIPROCATING BENDER FOR MAKING SUCCESSIVE BENDS IN METAL TUBES 0R RODS Filed Dec. 27, 1943 4 Sheets-Sheet 2 i Ijmuugw mlmml INVENTQE.

9 6 GQdriae Green Feb. 24-, 1948. G. GREENWOOD 2,436,542

RECIPROCATING BENDER FOR MAKING SUCCESSIVE BENDS IN METAL TUBES OR RODS v Filed Dec. 27, 1943 4 sheets sheet 3 lNvaNT fb Geare Greenwood gamma QATW- Feb 24, l

G. GREENWOOD (y j 2,43,642

RECIPROCATING BENDER FOR MAKING SUCCESSIVE BENDS IN METAL- TUBES OR RODS File d Dec.'2 7, 194s 4 Sheets-Shet 4' I INVENTOR- K I 1,

Patented Feb. 24, 1948 RECIPRO CATINGBENDER FOR MAKING SUCCESSIVE BENDS IN 'METAL ,TUBES R RODS G e Gr ve L d En land a i n?! o Blackburn Aircraft Limited, Brough, England Application December 2i, 1943, Serial No. 515,765

I n (I i-eat Britain January 4, 1343 4 Claims. (01. 153-44) This invention relates to improvements in bending tools for use in presses,"that is tosay, tools for bending tubes or "rods of circularor other cross section 1 from straight lengths into curved form.

Tools are already known which serve to bend a straight length of tube "or rod by pressure between two die members which define the shape of the bend required. In U. S. Patent No. 2,369,486 issued Feb. 13, 1945, a tool'is described in which the bending of the tubeftakes 'place'by relative movement between the'tube and a shaping die of gradually increasing curvature which ultimatelydefines the shape to be'imparted' to the tube. Also, in U. S. Patent No.'2,357,605 issued Sept; 5, 1944; there is described a. 'tool in which the tube after being first brought to a shape in one plane by either of the above kinds of tool is brought to a shape in another "plane by a shaping member moving relatively tothe shaping meansfirst employed for example besecured to a bridgepiece so that they are caused to move together relatively to the bed, and the cam 'me'mbersfare so shaped and their commencement displaced linearly that the one slidable thru'stmember is moved from its initial position to its opposite limit position before the complethe present invention'is to provide a tool for forming pronounced bends in rods or tubes. A further objectoi theinvention' is to provide a double acting tool so that at leastjtwo bends of similar or dissimilar curvature lying in the one plane may be formed at the one time by a single operation of the press inwhich the tool is located.

The tool according to the present invention consists of a bed on which islocated a form block adjacent which are at least two guide-ways at an angle to one another and each" having a slidable thrust element adapted to be moved by a cam member movable relatively to such bed whereby a-tube or rod located adjacent the form block is forced to take the shape defined thereby initially by the one slidable thrust member and finally by the second or another slidable thrust member on causing movement of the cam members relatively to the bed.

According to a further feature of the invention 1 the form block has a pair of shape defining surfaces or there are two form blocks, and two slidable thrust elements each in a guide-way are provided for each shapingsurface or each form.

mentary slidable thrust member commences to move. Where there are two pairs of slidable thrust members and associated cam members, the various camsmay operate sequentially or in pairs one after theother as may be appropriate for imparting a desired bend to a tube. In all cases the cam members are arranged to enter in slots in the bedfthe mouths of which slots serve asthe guide-ways for the slidable thrust members. The cam membersmay be guided by the "provision (ii guides which may be separately arrangedto guide them and the bridge member as a whole or ind vidually as by the provision of rails or similar projections which act in recesses in the slots in the bedtnrougn which the cam members pass.

The tool as a whole is conveniently made of wood but if desired the slots in the bed may be metal faced or faced with tough fibre in order to avoid wear. The working suriaces of the cam members as well as the faces of the slidable thrust members may also be fibre faced, although the latter may be made entirely of tough fibrous material.

In order that the invention may be clearly understood and readily carried into effect, embodiments of tools, in accordance with the invention are by way of example hereinafter more fully described with reference to the accompanying drawings which are given for purposes of illustration only and not of limitation.

In these drawings:

Figure 1 is a perspective view of a tool for forming a single bend to a rod or tube with the parts thereof shown in the position they occupy prior to use,

Figure 2 is a view similar to Figure 1 showing the'positions ofparts of the tool at the completion of the. first stage of its operation,

Figure 3 is again a similar view to Figure 1 showing the positions of the parts of the tool at the'completion of the second stage of its operation,

' Figure 4 is an under plan view of the tool of Figure 1; and

Figure 5 is a section taken on the line VV of Figure 4 shown on a somewhat larger scale.

Figure 'S is a perspective view of the movable has. 7 with the parts shown at the completion of the first stage of operation,

Figure 9 is again a view similar. to newer showing the parts at the completion of the secnd stage of operations, and

Figure is a plan view or the table of atool for imparting two bends to a rod br tube against two form blocks, a H

Referring now to the said drawings andin particular to Figures 1 to 5 thereof, the tool comprises a bed I which is supported on anll rality;

of legs 2 at a distance above the bed of the press in wh h zie lis et e w 9. th S a of the bed. I there is locateiia formsblock 3 adiaeent which are T58 a'jped siets 4, 5 which airlthe bed ena neve their arise at an angle to one ahot'her'jm exaniple at right asfsholwnjinthe dra rigs. The Shani; portions o'r feaphtrthe I pea slots 4 and 5 are faced with "strips of wear-resisting tough fibroiis material 4, and. 5 5 respectively. A slidable thrust memb'erj, 'l, which is conveniently of tough fibre material and is of substantially H shape seen on (see Figure 5), is arranged in the respective slots 4, '5 to ride along the wear-resisting portions 4 4 and 5 5 respectively. Each slidable thrust member I:

6,] engages aguide member and is drawn to the end of its respeetive slot furthest from the form block conveniently by means of a pair of springs 8, 8 the ends of which are attached to a cross bar '9 on the underside 'of a slidable thrust memher and to blocks (0,10 611 the under side of-the sloping portion I4 and a'plain'sided portion M A similar cam member l5 extends at right angles to the guide me'mber l3 and this cam member also has an inclined surface I5 The arrangeis s'n'ch that as the bridge piece is movedby the ram of a press-towards the bedi it is guided a;

by the guide memberslZ, l3 working in their slots in the bed j and the cam members I4, 45 enter the shank portionsof the slots 4, 5 so that their inclined surfaces I4 I5 engage and displace the slidable thrust members 6, l to move them along theslots in which they are located. The cam member i4 is longer than the cam member l5 and the arrangement is .such that during the first *stageuof movement. the ,slidable thrust member 6 is first moved ialongitsslotA by the inclined surfaceJM of; the. cam 14 and thereafter held in thatlimit position by the plain edge Mil. After the completion-,iof ,this initial operation the. sloping surface t 15% of the: cam

member l5 engages the slidable thrust member-,1

andcauses itto move, alon its slot 5 also until it reaches its opposite limit position, at Whlchtirne the bridge piece. tl has been moved itstmaxi mnm distance towardsthebed. al limited for example by the block 16 engagin'gmthe. surface of rtheibed. The lengths of the legs 2 are such that the guide members l2 and 13 may pass through the bed I to maximum possible extent without contacting the bed of the press. To restore the bridge piece H and the parts carried thereby to initial position a depending rod carried by the bridge piece H extends throu gh a leeve l1, mounted on the bed 1 and '9. spring I8 is disposed rund this rod such that the spring is compressed during movement of the bridge piece ll towards the bed I aridrheenerg stered by this spring returns the e autpjmatically to its initial position bridge on raising the arm of the press; The slidable g' hr1 1st rn en l i e rs; 6 gl are automatically returned ta the in i el b'si i y e Springs 81 d, after removing the bent rod or tube, the tool is read st r further tee;

In using this form of tool a tube I9 is located againstthe form block 3, for example by engaging in a recess therein where a short tube is in position as shown .injigures 1-to\3. On commeets or the fi narstase di or entin (see g ure, 2) the 'sli dabl hr ust member s. bypassing onthe. tiibe l9; aus'e'd "i rliobehd round to a curvature determined by the form blqckwith the end of the tube passed across. and in front .65 the sli'dabl'elthriist member l sothatwhen that thrust m Inber is moyedfit thithe displaces the end of. e tube arid ,causesjit ,finally to take the sha .defirree V by the omplete fforr'n block see ay be seen i grgure 3. The bent tube is "5thstantially c n eferring or the in'gs, the g i eraifagrraiige nt. or the, tool rbjr mparnn two bendsto area 6;: tube here tratedjis s Tar t theslng'le bend tbol already describedv anjd a; "1y comprises, a bed 21:, similarly su pqrtd lurality. of legs, on this surface of whieh bed is prbvided arena block 2; havin all ODPQSeQIpair 'lof sh'aping terraces 2e: 2 meant h rms sp e w i a pair of angmarry hisiidseirslets 24, 7251s; whim act slidable, thrustmmembefs 1125,12] rfif l ctively. najac pqthe other shapifigsiifface. 23 is other pair at "sealant d1 'd 's1ots 28, 2 9 n which aet siid bie thriist members age, 31. 'A

' p fqeaa na mttnerormpioc zstp 1 Wh'ibh a rate .33 may be uh may. he determined bynlocation blocks the 5- 'I' ehtfl h y lg' fibt b fe ii-art. E eii' H) his "@0151 "Sign; 1;; 'ris sfa triage fat when in this case has four depending "guide members @l, 3Q, 39, lll carrying cam members fll, E2, 13 and .41 frespeetij iely tl-he members Mi, .4? e f i t .I iii t t em @12 e fi we th aiemb ;.-A JA-. a ass-q: l l s il sn r are e attam mem s Aler la he ot 2:1 ees eqt elwhi s th @1 mates 4 estia he'slets. 2 fise eeqev ly- Puti in ia s .ee3- e emM -M in? 9 the r, lqeiu e igiee fi .94 m e t e j y t r stmfl he i e9 t a 'si i taneously partiallpbendrthe tube 33 around the shaping stresses 2& r gees templa es gs; teem remee efitha fi e tme b 'e v ft 3.- li i e 2. -.ih a p; th wa a r i e and in front o ethrusbmembers v illustrated in Figures 7 to 9 in which there are two form blocks 60, 53 disposed side by side to leave a channel to accommodate a tube 33, the ends of which tube are located as in the previous example by blocks 34, 35. Adjacent the shaping surface 60 of the form block 60 are a pair of slots 45, 46 similar to the pair of slots 24, 25 and adjacent the shaping surface 53 of the form block 53 is another pair of slots 41, 48 also similar to the slots 24, 25 but displaced 180 with respect to the other pair of slots. In this case thecam members effective on the thrust members 49, 50 in the slots 45, 41 are of similar shape and extent and by their movement bend the tube 33 in opposite directions about the respective form blocks 60, 53 substantially similar amounts. The thrust members 52 in the slots 46, 48 are next brought into operation by cam members which are also of similar shape and extent, similar to the cam members 42, 44 to complete the bending of the tube to the shape defined by the form blocks 60, 53 so that the resultant tube is substantially S-shaped.

The shaping surfaces 23 23 may be of different curvature or the surfaces of the two form blocks 69, 53 may be differently curved when the timing of the coming into operation of the cam members may be altered so that the thrust members move at different times, for example one after the other, thus the shaping of one end of a tube may be complete before the shaping of the other end, or one end of the tube may be partially bent at the time the bending of the other end thereof starts.

In the bending of a tube by tools such as described above, the tubes are filled with any convenient filler known in the art, such as sand, resin, or a low temperature melting point alloy. Such fillers virtually make the tube into a solid rod, and wherever a tube is mentioned herein that term is intended to include the alternative, namely a solid rod or bar.

I claim:

1. A tool for bending tubes and rods including a base board, a form block having a shaping surface mounted on said base board, at least two angularly disposed slots in said base board adjacent the shaping surface of said form block, a thrust member slidable in each of the slots, means to hold part of an elongated tube or rod to be bent on said base board in contact with said form block with another part of said tube or rod projecting into the path of one of said thrust members, and means acting through said slots for moving said thrust members along their slots in succession whereby said thrust member into the path of which the tube or rod projects moves first to effect a partial bending so as to bring a third part of the tube or rod into the path of the other thrust member which subsequently completes the bending operation in the same direction.

2. A tool for bending tubes and rods, including a base, a form block having a pair of opposed shaping surfaces on said base, a separate pair of angularly disposed slots in said base adjacent each of the shaping surfaces of said form block, pairs of thrust members slidable in said pairs of slots, respectively, means to hold the central portion of an elongated tube or rod on said base in a fixed position in which portions of said tube or rod adjacent said center portion are in contact with corresponding points of said two shaping surfaces, respectively, with the outer portions of the tube or rod projecting into the paths of one of the thrust members of each pair, respectively, and means acting through said slots for moving the thrust members of each pair along their slots in a predetermined succession, whereby said first mentioned thrust members, into the paths of which the outer portions of the tube or rod project, move simultaneously in substantially the same direction to effect a partial bending so as to bring the ends of the tube or rod into the paths of the other thrust members of the corresponding pairs which subsequently move towards each other to complete the bending operation.

3. A tool forbending tubes and rods, including a platform supported above the bed of a press, a shape defining member mounted on the upper surface of said platform, at least one pair of angularly displaced slots in said platform extending away from said shape defining member, a'thrust member slidable in each of said slots, transverse enlargements to each of said slots, a bridge member movable by the ram of the press towards said platform, guide members attached to said bridge member and each acting in the enlargement of one of said slots, and a cam member mounted fast with each guide member and engaging a thrust member to move it along its slot.

4. A tool for bending tubes and rods including a base having its upper surface spaced above the bed of a press, at least one form block having a shape defining surface mounted on said upper surface, a pair of angularly displaced slots in said upper surface extending away from each shaping surface, a thrust member in each of said slots, spring means urging said thrust members towards the ends of their slots remote from said shaping surface, transverse enlargements at the remote ends of each of said slots, a bridge member movable by the ram-of the press towards the upper surface of said base, spring means tending to move said bridge member away from said upper surface, guide members attached to said bridge member and each acting in an enlargement of one of said slots, and a cam member having an inclined working surface fast with each guide member in relative linear displacement to bring their inclined surface into operative engagement with a thrust member in predetermined order.

GEORGE GREENWOOD.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 137,792 Newsham Apr. 15, 1873 439,350 Hambay Oct. 28, 1890 829,838 Brown Aug. 28, 1906 1,326,852 Dallmeyer et al. Dec. 30, 1919 1,433,880 Fancher et a1 Oct. 31, 1922 1,474,882 Baumgarten Nov. 20, 1923 1,492,411 Anderson Apr. 29, 1924 1,586,627 Kominsky June 1, 1926 1,706,274 Woodings Mar. 19, 1929 1,721,636 OBrien July 23, 1929 1,787,151 Groehn Dec. 30, 1930 1,183,523 Bauroth May 16, 1916 1,807,824 Booth June 2, 1931 2,357,605 Nivision Sept. 5, 1944 

